What absorbs at 1127 cm⁻¹ in an FTIR spectrum?
A band near 1127 cm⁻¹ can point to several functional groups. Below are the most likely assignments, ranked by how much published evidence supports each — every one traceable to literature (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Quick answer
A band near 1127 cm⁻¹ is usually interpreted by checking which functional groups repeatedly co-occur there in the literature, then confirming at least one or two additional peaks in the same sample. This page ranks those assignments by accumulated evidence rather than by a single fixed textbook rule.
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Methoxy (OCH3) | 5 | 5 | 1.0 |
| Methacrylate | 5 | 5 | 1.0 |
| Acetate | 5 | 5 | 1.0 |
| C-O single bond | 5 | 5 | 1.0 |
| Alkyl C-H | 4 | 4 | 1.0 |
| Carboxyl (COOH) | 3 | 3 | 1.0 |
| Carbon dioxide | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| Chlorine | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Phosphorus | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 0.9 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| chitosan | 1127, 1650, 1655 | Acetate, Methacrylate, C-O single bond | 1 |
| cellulose | 1127, 1735, 1650 | Acetate, Methacrylate, C-O single bond | 1 |
| hemicellulose | 1127, 1730, 897 | Methacrylate, Acetate, C-O single bond | 1 |
| nanotubes | 1127, 1735, 1630 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| cotton fabric | 1127, 900, 862 | Methacrylate, Acetate, C-O single bond | 1 |
| chitin | 1127, 1650, 1655 | Methacrylate, Acetate, C-O single bond | 1 |
Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.
Spectrum logic
This band becomes meaningful only when read with its neighboring peaks. In practice, analysts first look at the assignments above, then check whether the same sample also shows other peaks expected for the same structural motif. A lone band near 1127 cm⁻¹ is usually not enough for material identification by itself.
Real-world usage
This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.
Common mistakes
- Treating one isolated band as proof of a material without checking at least one or two supporting peaks.
- Ignoring overlap: multiple functional groups can contribute near the same wavenumber.
- Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.
Verification advice
When ambiguity remains, validate the hypothesis with DSC, GC-MS, or TGA, especially for blends, degraded samples, and filled polymers.
Literature behind these assignments
-
Carbohydrate confidence 1.0
“References The glycogen band (1127 blue shifted at 1 h and conInstitutet tinued to increase by 6 and 24 h (Fig.”
Shi 等 - 2018 - Biochemical alterations of Candida albicans during DOI: 10.1039/c8an01452c -
Carboxyl (COOH) confidence 1.0
“The intensity of subbands at 1127 and 1110 A correlated with the acid phosphate content in these models.”
Spevak 等 - 2013 - Fourier Transform Infrared Spectroscopic Imaging P DOI: 10.1007/s00223-013-9695-9. -
Acetate confidence 1.0
“Sulfation of NTPS and ATPS 1127cm-1 absorption band at may be caused by antisymmetric Table1showedtheyieldsandDSofNTPS-SandATPS-Sobtained stretching vibration of C-O-S [15].”
Wang 等 - 2010 - Sulfation of tea polysaccharides Synthesis, chara DOI: 10.1016/j.ijbiomac.2009.12.007 -
Hydrogen bond confidence 1.0
“The band intensities were decreased at 3411 cm-1 (O-H (C-O stretching) and 1127 stretching) due to the existence of a hydrogen bond, reduction of water and cellulose contents in bio-char.”
Bio-Char Characterization Produced from Walnut Shell Biomass through Slow Pyrolysis: Sustainable for Soil Amendment and an Alternate Bio-Fuel DOI: 10.3390/en15010001 -
Acetate confidence 1.0
“The band at 1127 cm-1 C-O indicated the C-O stretching vibrations in alcohols, phenols, or ether or ester groups [41].”
Basheer 等 - 2020 - Synthesis, Characterization, and Analysis of Hybri DOI: 10.3390/polym12061305 -
Ester confidence 1.0
“However, the presence of the band at 1127 cm-1, C=O that belongs to the stretching of of ester groups.”
Cutin from Solanum Myriacanthum Dunal and Solanum Aculeatissimum Jacq. as a Potential Raw Material for Biopolymers DOI: 10.3390/polym12091945 -
Alkyl C-H confidence 1.0
“(asymmetrical C-H bending of the CH2 group), 1127cm-1 and (C3-O stretching).”
Biswas 等 - 2017 - Facile Preparation of Biocomposite from Prawn Shel DOI: 10.1155/2017/6472131 -
C-O single bond confidence 1.0
“C-O stretching 1093 C-O-C glycosidic linkage vibration (Asym) 1117 C-O-C glycosidic linkage vibration (Sym) 1127”
Cuiffo 等 - 2021 - Thermochemical degradation of cotton fabric under DOI: 10.1186/s40691-021-00263-8
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